Recombinant human activated protein C for severe sepsis in neonates

Protein C Pathway in Paediatric and Neonatal Sepsis

Protein C plays a major role in the physiological regulation of coagulation pathways through inactivation of factor Va, factor VIIIa, and plasminogen activator inhibitor. Protein C is involved in the control of inflammation during sepsis, by inhibiting release of pro-inflammatory cytokines, thereby controlling neutrophil, and monocyte effects on injured tissue. Recombinant human activated protein C (rhAPC) reduced mortality in adult sepsis in earlier studies but had no significant benefit in more recent trials. Protein C levels are reduced during paediatric and neonatal sepsis, which may play a major role in the development of disseminated intravascular thrombosis, purpura fulminans, and multiorgan dysfunction. The role of protein C in paediatric sepsis requires further clinical and immunological evaluation to define the patient subgroups who may benefit from this therapy. Newer versions of rhAPC are under development with less risk of haemorrhage potentially broadening the scope of this intervention.

Fast I(n)dentification of Pathogens in Neonates (FINDPATH-N): protocol for a prospective pilot cohort study of next-generation sequencing for pathogen identification in neonates with suspected sepsis

INTRODUCTION

Sepsis is a major source of morbidity and mortality in neonates; however, identification of the causative pathogens is challenging. Many neonates have negative blood cultures despite clinical evidence of sepsis. Next-generation sequencing (NGS) is a high-throughput, parallel sequencing technique for DNA. Pathogen-targeted enrichment followed by NGS has the potential to be more sensitive and faster than current gold-standard blood culture. In this pilot study, we will test the feasibility and pathogen detection patterns of pathogen-targeted NGS in neonates with suspected sepsis. Additionally, the distribution and diagnostic accuracy of biomarkers cell-free DNA and protein C levels at two time points will be explored.

METHODS AND ANALYSIS

We will conduct a prospective, pilot observational study. Neonates over 1 kg with suspected sepsis from a single tertiary care children's hospital will be recruited for the study. Recruitment will be censored at 200 events or 6 months' duration. Two blood study samples will be taken: the first simultaneous to the blood culture (time=0 hour, for NGS and biomarkers) via an exception to consent (deferred consent) and another 24 hours later after prospective consent (biomarkers only). Neonates will be adjudicated into those with clinical sepsis, culture-proven sepsis and without sepsis based on clinical criteria. Feasibility parameters (eg, recruitment) and NGS process time will be reported.For analysis, NGS results will be described in aggregate, compared with the simultaneous blood culture (sensitivity and specificity) and reviewed via expert panel for plausibility. Pilot data for biomarker distribution and diagnostic accuracy (sensitivity and specificity) for distinguishing between septic and non-septic neonates will be reported.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Hamilton Integrated Research Ethics Board. We will seek publication of study results in peer-reviewed journals.

A Systematic Summary of Systematic Reviews on Anticoagulant Therapy in Sepsis

Many systematic reviews have been published regarding anticoagulant therapy in sepsis, among which there is substantial heterogeneity. This study aimed to provide an overview of existing systematic reviews of randomized controlled trials by using a comprehensive search method. We searched MEDLINE, EMBASE, and Cochrane Database of Systematic Reviews. Of 895 records screened, 19 systematic reviews were included. The target agent was as follows: antithrombin (n = 4), recombinant thrombomodulin (n = 3), heparin (n = 3), recombinant activated protein C (n = 8), and all anticoagulants (n = 1). Antithrombin did not improve mortality in critically ill patients but indicated a beneficial effect in sepsis-induced disseminated intravascular coagulation (DIC), although the certainty of evidence was judged as low. Recombinant thrombomodulin was associated with a trend in reduced mortality in sepsis with coagulopathy with no increased risk of bleeding, although the difference was not statistically significant and the required information size for any declarative judgement insufficient. Although three systematic reviews showed potential survival benefits of unfractionated heparin and low-molecular-weight heparin in patients with sepsis, trials with low risk of bias were lacking, and the overall impact remains unclear. None of the meta-analyses of recombinant activated protein C showed beneficial effects in sepsis. In summary, a beneficial effect was not observed in overall sepsis in poorly characterized patient groups but was observed in sepsis-induced DIC or sepsis with coagulopathy in more specific patient groups. This umbrella review of anticoagulant therapy suggests that characteristics of the target populations resulted in heterogeneity among the systematic reviews.

Recombinant human activated protein C for severe sepsis in neonates

BACKGROUND

Sepsis is a common problem in preterm and term infants. The incidence of neonatal sepsis has declined, but mortality remains high. Recombinant human activated protein C (rhAPC) possess a broad spectrum of activity modulating coagulation and inflammation. In septic adults it may reduce mortality, but no significant benefit has been reported in children with severe sepsis.

OBJECTIVES

To determine whether treatment with rhAPC reduces mortality and/or morbidity in neonatal sepsis.

SEARCH METHODS

For this update searches were carried out in May 2011 of the Cochrane Central Register of Controlled Trials (The Cochrane Library), MEDLINE, EMBASE, CINAHL, and abstracts of annual meetings of the Pediatric Academic Societies. Doctoral dissertations, theses and the Science Citation Index for articles on activated protein C were searched. No language restriction was applied.

SELECTION CRITERIA

Randomized or quasi-randomized trials, assessing the efficacy of rhAPC compared to placebo or no intervention as an adjunct to antibiotic therapy of suspected or confirmed severe sepsis in term and preterm infants less than 28 days old. Eligible trials should report at least one of the following outcomes: mortality during initial hospital stay, neurodevelopmental assessment at two years of age or later, length of hospital stay, duration of ventilation, chronic lung disease, periventricular leukomalacia, intraventricular haemorrhage, necrotizing enterocolitis, bleeding, and any other adverse events.

DATA COLLECTION AND ANALYSIS

Review authors were to independently evaluate the articles for inclusion criteria and quality, and abstract information for the outcomes of interest. Differences were to be resolved by consensus. The statistical methods were to include relative risk, risk difference, number needed to treat to benefit or number needed to treat to harm for dichotomous and weighed mean difference for continuous outcomes reported with 95% confidence intervals. A fixed effect model was to be used for meta-analysis. Heterogeneity tests, including the I(2) statistic, were to be performed to assess the appropriateness of pooling the data.

MAIN RESULTS

No eligible trials were identified. In October 2011 rhAPC (Xigris®) was withdrawn from the market by Eli Lilly due to a higher mortality in a trial among adults. Xigris® (DrotAA)( rhAPC) should no longer be used in any age category and the product should be returned to the distributor.

AUTHORS' CONCLUSIONS

Despite the scientific rationale for its use, there is insufficient data to use rhAPC for the management of severe sepsis in newborn infants. Due to the results among adults with lack of efficacy, an increase in bleeding and resulting withdrawal of rhAPC from the market, neonates should not be treated with rhAPC and further trials should not be conducted.

Human recombinant activated protein C for severe sepsis

BACKGROUND

Sepsis is a common and frequently fatal condition. Human recombinant activated protein C (APC) has been used to reduce the high rate of death by severe sepsis or septic shock. This is an update of a Cochrane review (originally published in 2007 and updated in 2008).

OBJECTIVES

We assessed the clinical effectiveness and safety of APC for the treatment of patients with severe sepsis or septic shock.

SEARCH METHODS

For this updated review we searched CENTRAL (The Cochrane Library 2010, Issue 6); MEDLINE (1966 to June 2010); EMBASE (1980 to July 1, 2010); BIOSIS (1965 to July 1, 2010); CINAHL (1982 to 16 June 2010) and LILACS (1982 to 16 June 2010). There was no language restriction.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) assessing the effects of APC for severe sepsis in adults and children. We excluded studies on neonates. We considered all-cause mortality at day 28, at the end of study follow up, and hospital mortality as the primary outcomes.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a random-effects model.

MAIN RESULTS

We identified one new RCT in this update. We included a total of five RCTs involving 5101 participants. For 28-day mortality, APC did not reduce the risk of death in adult participants with severe sepsis (pooled RR 0.97, 95% confidence interval (CI) 0.78 to 1.22; P = 0.82, I(2) = 68%). APC use was associated with an increased risk of bleeding (RR 1.47, 95% CI 1.09 to 2.00; P = 0.01, I(2) = 0%). In paediatric patients, APC did not reduce the risk of death (RR 0.98, 95% CI 0.66 to 1.46; P = 0.93). Although the included trials had no major limitations most of them modified their original completion or recruitment protocols.

AUTHORS' CONCLUSIONS

This updated review found no evidence suggesting that APC should be used for treating patients with severe sepsis or septic shock. Additionally, APC is associated with a higher risk of bleeding. Unless additional RCTs provide evidence of a treatment effect, policy-makers, clinicians and academics should not promote the use of APC.Warning: On October 25th 2011, the European Medicines Agency issued a press release on the worldwide withdrawal of Xigris (activated protein C / drotrecogin alfa) from the market by Eli Lilly due to lack of beneficial effect on 28-day mortality in the PROWESS-SHOCK study. Furthermore, Eli Lily has announced the discontinuation of all other ongoing clinical trials. The final results of the PROWESS-SHOCK study are expected to be published in 2012. This systematic review will be updated when results of the PROWESS-SHOCK or other trials are published.

Targeting inflammation to prevent bronchopulmonary dysplasia: can new insights be translated into therapies?

Bronchopulmonary dysplasia (BPD) frequently complicates preterm birth and leads to significant long-term morbidity. Unfortunately, few therapies are known to effectively prevent or treat BPD. Ongoing research has been focusing on potential therapies to limit inflammation in the preterm lung. In this review we highlight recent bench and clinical research aimed at understanding the role of inflammation in the pathogenesis of BPD. We also critically assess currently used therapies and promising developments in the field.

Human recombinant activated protein C for severe sepsis

BACKGROUND

Sepsis is a common and frequently fatal condition. Human recombinant activated protein C (APC) has been used to reduce the high rate of death by severe sepsis or septic shock. This is an update of a Cochrane review (originally published in 2007 and updated in 2008).

OBJECTIVES

We assessed the clinical effectiveness and safety of APC for the treatment of patients with severe sepsis or septic shock.

SEARCH STRATEGY

For this updated review we searched CENTRAL (The Cochrane Library 2010, Issue 6); MEDLINE (1966 to June 2010); EMBASE (1980 to July 1, 2010); BIOSIS (1965 to July 1, 2010); CINAHL (1982 to 16 June 2010) and LILACS (1982 to 16 June 2010). There was no language restriction.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) assessing the effects of APC for severe sepsis in adults and children. We excluded studies on neonates. We considered all-cause mortality at day 28, at the end of study follow up, and hospital mortality as the primary outcomes.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, risk of bias assessment and data extraction. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic. We used a random-effects model.

MAIN RESULTS

We identified one new RCT in this update. We included a total of five RCTs involving 5101 participants. For 28-day mortality, APC did not reduce the risk of death in adult participants with severe sepsis (pooled RR 0.97, 95% confidence interval (CI) 0.78 to 1.22; P = 0.82, I(2) = 68%). APC use was associated with an increased risk of bleeding (RR 1.47, 95% CI 1.09 to 2.00; P = 0.01, I(2) = 0%). In paediatric patients, APC did not reduce the risk of death (RR 0.98, 95% CI 0.66 to 1.46; P = 0.93). Although the included trials had no major limitations most of them modified their original completion or recruitment protocols.

AUTHORS' CONCLUSIONS

This updated review found no evidence suggesting that APC should be used for treating patients with severe sepsis or septic shock. Additionally, APC is associated with a higher risk of bleeding. Unless additional RCTs provide evidence of a treatment effect, policy-makers, clinicians and academics should not promote the use of APC.

Adjunctive immunologic interventions in neonatal sepsis

Because of inadequate sample sizes of randomized controlled trials, few immunologic interventions to treat or prevent neonatal sepsis have been reliably evaluated. International collaboration is essential in achieving timely, adequate samples to assess effects on mortality or disability-free survival reliably. Promising or possible therapeutic interventions in severe or gram-negative sepsis include exchange transfusions, pentoxifylline, and IgM-enriched intravenous immunoglobulin. Promising or possible prophylactic interventions include lactoferrin, with or without a probiotic; selenium; early curtailment of antibiotics after sterile cultures; breast milk; and earlier initiation of colostrum in high risk preterm infants. Prophylactic oral probiotics are safe and effective (P<.00001) in reducing all-cause mortality and necrotizing enterocolitis in preterm infants by over half, but do not reduce sepsis.

Protein C preserves microcirculation in a model of neonatal septic shock

OBJECTIVES

Sepsis remains a disease with a high mortality in neonates. Microcirculatory impairment plays a pivotal role in the development of multiorgan failure in septic newborns. The hemodynamic effects of recombinant activated protein C (rhAPC) were tested in an animal model of neonatal septic shock focusing on intestinal microcirculation.

MATERIALS AND METHODS

Endotoxic shock was triggered by intravenous application of Escherichia coli lipopolysaccarides in newborn piglets. Thereafter, five animals received a continuous infusion of 24 microg/kg/h rhAPC, and five received vehicle for control. Over the course of three hours, intestinal microcirculation was assessed by intravital microscopy every 30 min. Macrocirculation and blood counts were monitored simultaneously.

RESULTS

After a short hypotensive period in all animals, the arterial blood pressure returned to baseline in the rhAPC-treated piglets, whereas the hypotension became increasingly severe in the controls. By 90 min, mean blood pressure in the controls was significantly lower than in the treatment group. Similar observations were made regaring microcirculation. After an early impairment in all study animals, functional capillary density and intestinal microcirculatory red blood cell velocity and red blood cell flow recovered in the rhAPC group, but deteriorated further in the control piglets.

CONCLUSION

Recombinant activated protein C protects macro- and microcirculation from endotoxic shock.

Potential of immunomodulatory agents for prevention and treatment of neonatal sepsis

Prevention of neonatal infection-related mortality represents a significant global challenge particularly in the vulnerable premature population. The increased risk of death from sepsis is likely due to the specific immune deficits found in the neonate as compared to the adult. Stimulation of the neonatal immune system to prevent and/or treat infection has been attempted in the past largely without success. In this review, we identify some of the known deficits in the neonatal immune system and their clinical impact, summarize previous attempts at immunomodulation and the outcomes of these interventions, and discuss the potential of novel immunomodulatory therapies to improve neonatal sepsis outcome.

Bench-to-bedside review: Developmental influences on the mechanisms, treatment and outcomes of cardiovascular dysfunction in neonatal versus adult sepsis

Sepsis is a significant cause of morbidity and mortality in neonates and adults, and the mortality rate doubles in patients who develop cardiovascular dysfunction and septic shock. Sepsis is especially devastating in the neonatal population, as it is one of the leading causes of death for hospitalized infants. In the neonate, there are multiple developmental alterations in both the response to pathogens and the response to treatment that distinguish this age group from adults. Differences in innate immunity and cytokine response may predispose neonates to the harmful effects of pro-inflammatory cytokines and oxidative stress, leading to severe organ dysfunction and sequelae during infection and inflammation. Underlying differences in cardiovascular anatomy, function and response to treatment may further alter the neonate's response to pathogen exposure. Unlike adults, little is known about the cardiovascular response to sepsis in the neonate. In addition, recent research has demonstrated that the mechanisms, inflammatory response, response to treatment and outcome of neonatal sepsis vary not only from that of adults, but vary among neonates based on gestational age. The goal of the present article is to review key pathophysiologic aspects of sepsis-related cardiovascular dysfunction, with an emphasis on defining known differences between adult and neonatal populations. Investigations of these relationships may ultimately lead to 'neonate-specific' therapeutic strategies for this devastating and costly medical problem.

Human recombinant activated protein C for severe sepsis

BACKGROUND

Sepsis is a common, expensive and frequently fatal condition. There is an urgent need for developing new therapies to further reduce severe sepsis-induced mortality. One of those approaches is the use of human recombinant activated protein C (APC).

OBJECTIVES

We assessed the clinical effectiveness of APC for the treatment of patients with severe sepsis or septic shock.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, Issue 2); MEDLINE (1966 to 2005); EMBASE (1980 to 2005) and LILACS (1982 to 2005). We contacted researchers and organizations working in the field. We did not have any language restriction.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) assessing the effects of APC for severe sepsis in adults and children. We excluded studies on neonates.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, quality assessment and data extraction. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using I-squared (I(2)). We used a random-effects model.

MAIN RESULTS

We included four studies involving 4911 participants (4434 adults and 477 paediatric patients). For 28-day mortality, APC did not reduce the risk of death in adult participants with severe sepsis (pooled RR 0.92, 95% confidence interval (CI) 0.72 to 1.18; P = 0.50, I(2) = 72%). The effectiveness of APC did not seem to be associated with the degree of severity of sepsis (two studies): for an APACHE II score less than 25 the RR was 1.04 (95% CI 0.89 to 1.21; P = 0.70), and in participants with an APACHE II score of 25 or more the RR was 0.90 (95% CI 0.54 to 1.49; P = 0.68). APC use was, however, associated with a higher risk of bleeding (RR 1.48 (95% CI 1.07 to 2.06; P = 0.02, I(2) = 8%). Two studies were stopped early because there was little chance of reaching the efficacy endpoint by completion of the trial.

AUTHORS' CONCLUSIONS

This updated review found no evidence suggesting that APC should be used for treating patients with severe sepsis or septic shock. Additionally, APC seems to be associated with a higher risk of bleeding. Unless additional RCTs provide evidence of a treatment effect, policy-makers, clinicians and academics should not promote the use of APC.

Human recombinant activated protein C for severe sepsis

BACKGROUND

Sepsis is a common, expensive and frequently fatal condition. There is an urgent need for developing new therapies to further reduce severe sepsis-induced mortality. One of those approaches is the use of human recombinant activated protein C (APC).

OBJECTIVES

We assessed the clinical effectiveness of APC for the treatment of patients with severe sepsis or septic shock.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2005, Issue 2); MEDLINE (1966 to 2005); EMBASE (1980 to 2005) and LILACS (1982 to 2005). We contacted researchers and organizations working in the field. We did not have any language restriction.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) assessing the effects of APC for severe sepsis in adults and children. We excluded neonates.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, quality assessment and data extraction. We estimated relative risks (RR) for dichotomous outcomes. We measured statistical heterogeneity using I-squared (I(2)). We used a random-effects model.

MAIN RESULTS

We included four studies involving 4911 participants (4434 adults and 477 paediatric patients). For 28-day mortality, APC did not reduce the risk of death in adult participants with severe sepsis (pooled RR 0.92, 95% confidence interval (CI) 0.72 to 1.18; P = 0.50, I(2) = 72%). The effectiveness of APC did not seem to be associated with the degree of severity of sepsis (two studies): for an APACHE II score less than 25 the RR was 1.04 (95% CI 0.89 to 1.21; P = 0.70), and in participants with an APACHE II score of 25 or more the RR was 0.90 (95% CI 0.54 to 1.49; P = 0.68). APC use was, however, associated with a higher risk of bleeding (RR 1.48 (95% CI 1.07 to 2.06; P = 0.02, I(2) = 8%). Two studies were stopped early because there was little chance of reaching the efficacy endpoint by completion of the trial.

AUTHORS' CONCLUSIONS

This review suggests that APC should not be used in sepsis with an APACHE II score of less than 25 or, in paediatric patients. There is very weak evidence supporting APC use in patients with severe sepsis and at high-risk of death. As a result, policy-makers, clinicians and academics should be cautious when promoting the use of APC to patients with severe sepsis and an APACHE II score of 25 or greater. There is a need for further RCTs to answer with certainty what the role of APC is for patients with severe sepsis and an APACHE II score of at least 25. Those RCTs should be designed and conducted by non-profit organizations.

Evidence-based medicine: classifying the evidence from clinical trials--the need to consider other dimensions

The current approach to assessing the quality of evidence obtained from clinical trials focuses on three dimensions: the quality of the design (with double-blinded randomised controlled trials representing the highest level of such design); the statistical power (beta) and the level of significance (alpha). While these aspects are important, we argue that other significant aspects of trial quality impinge upon the truthfulness of the findings: biological plausibility, reproducibility and generalisability. We present several recent studies in critical care medicine where the design, beta and alpha components of the study are seemingly satisfactory but where the aspects of biological plausibility, reproducibility and generalisability show serious limitations. Accordingly, we argue for more reflection, definition and consensus on these aspects of the evaluation of evidence.